GeoViz: interactive maps that help people think

This issue of IJGIS showcases research activities related to how map displays can support users in visuospatial decision making for solving complex spatiotemporal problems. It represents a selection of the contributions made to a dedicated scientific workshop organized by the International Cartographic Association (ICA) Commissions on Geovisualization and Cognitive Visualization. The workshop was held over 3 days, from 6–8 March 2013, at HafenCity University in Hamburg, Germany. Sources of spatial data abound. Some spatial data are well-structured, some are messy, and others are streaming in at fast rates. Some data sets are so large that they have been creatively termed ‘big data’. Analysing and synthesising these messy, large and fast changing data sets to produce meaningful insights about phenomena and processes provides both computational and cognitive challenges. While computers can provide answers, people are required to make these answers meaningful. At the same time, the world faces significant problems that are affecting or will soon begin to affect our daily lives: food security, climate change and environmental hazards, traffic congestion, economic crises and biodiversity, amongst others. But both computers and people can do amazing things when tasked with a challenge. These amazing things, however, do not arise out of nowhere. They require a concerted effort to design interactive analytical cartographic representations of these messy, big and potentially rapidly changing data sets; representations that can effectively support spatiotemporal inference and decision making by people (Andrienko et al. 2010). Thus there is a need to bring together researchers who can contribute to our understanding of how technology, people and spatial representations of information work effectively together to solve the world’s pressing problems. The specialist workshop brought together 76 researchers from 18 countries working on the design, implementation and evaluation of interactive analytical cartographic representations. The workshop programme was derived from 44 submissions, and included 36 presentations grouped into 12 sessions of regular talks presenting mature research, minitalks presenting works in progress, and Birds of a Feather discussions about emerging topics such as uncertainty visualization and the use of colour. Based on the reviews of submitted extended abstracts and presentations at the workshop, the guest editors invited authors of the 10 most highly ranked regular presentations to submit full articles to this special issue. Each submission was reviewed by two to three external reviewers and the guest editors to protect anonymity of reviewers. The guest editors handled contributions by two of the conference co-organizers separately, to assure a fair and transparent review process. After several rounds of reviewing, five articles have been accepted for the special issue. These articles exemplify current research directions in geovisualization. We are very grateful to the reviewers and the authors for their diligent and extremely efficient work. It is notable that the reviewers not only critiqued the articles but also gave concrete recommendations to the authors for their improvement through revision. Turdukulov and colleagues describe a novel algorithm for detecting flock patterns in trajectory data sets. The proposed algorithm uses transaction-based data representations of International Journal of Geographical Information Science, 2014 http://dx.doi.org/10.1080/13658816.2014.937719